<div id="controls">
  <button id="start">start</button>
</div>
<div id="stage">
  <div>
    <div id="targetRoot" class="container">
      <div id="targetA" class="container">
        <div id="targetB" class="container">
          <div id="targetC" class="container">
            <div id="resizeC" class="resize">UpdatesC: <span id="updatesC"></span></div>
          </div>
          <div id="resizeB" class="resize">UpdatesB: <span id="updatesB"></span></div>
        </div>
        <div id="resizeA" class="resize">UpdatesA: <span id="updatesA"></span></div>
      </div>
      <div id="resizeRoot" class="resize">UpdatesRoot: <span id="updatesRoot"></span></div>
    </div>
  </div>
</div>
